The present invention relates to an all-purpose pressing-bending machine.
Prior pressing-bending machines conventionally comprise a feeding or supplying system, including a single central gear wheel, for feeding the material to be bent, operating the press and driving the mechanical slides provided for bending said material.
In particular, the mechanical slides are provided with a plurality of cams for translating a rotary movement derived from the central gear wheel into a translation movement on the piece to be bent.
This system, however, is affected by a first drawback due to the fact that the driving of the cams is derived from the central wheel movement, thereby for each type of machining a specific cam set would be required.
This, as it should be apparent, would involve a comparatively high time for properly equipping the machine, thereby negatively affecting the cost and product making time.
A further problem of prior pressing-bending machines is that the designing of a novel type of machining would be very fatiguing and expensive since, to that end, it would be necessary to design again a novel specific set of cams.
Accordingly, the aim of the present invention is to provide an all-purpose pressing-bending machine having very good operating features, and obviating the above mentioned drawbacks.
The above mentioned aim, as well as yet other objects, which will become more apparent hereinafter, are achieved by the present invention which specifically relates to an all-purpose pressing-bending machine, comprising a plurality of bending tool supporting slides, coupled to a supporting plate, and feeding means for feeding a material to be bent, characterized in that at least one of said bending tool supporting slides can be operated independently from the other slides by a corresponding motor-reducing unit, each said motor-reducing unit being coupled to electronic control means.
According to a preferred embodiment of the present invention, with each bending tool supporting slide a single cam pair is associated, each cam of said cam pair being adapted to translate a rotary movement of the motor into a translation movement of the bending tool supporting slide, said cam pairs being each formed by universal cams offset of 180xc2x0 from one another.
According to another preferred embodiment of the present invention, the translation movement of the bending tool supporting slide is obtained by modifying the time evolvement of the current circulating through the respective motor.
According to another preferred embodiment of the present invention, the feeding means for feeding said material to be bent comprise a roller feeding assembly which is driven by independent driving means and has a programmable operating pitch.
According to a further embodiment of the present invention, the machine comprises a programmable central core, which is independently driven, arranged at the center of the bending tool supporting slide supporting plate, and having a longitudinal movement with respect to said supporting plate for ejecting a workpiece or for sequentially driving the bending abutment core.
According to yet another preferred embodiment of the present invention, the all-purpose pressing-bending machine comprising a press, arranged upstream of said bending tool supporting slides and outside of the operating circumference thereof, said press being provided with a driving motor which is independent from the motor reducing units coupled to said bending tool supporting slides.
In particular, the press comprises a D.C. motor, cooperating with a braking-clutching device, which can be remotely controlled, and with a xe2x80x9cone-shotxe2x80x9d device, thereby affording the possibility of performing different types of machining cycles.
Moreover, the press is provided with an independent drive along an axis having a direction substantially parallel to the material being processed feeding direction.
Finally, the machine electronic control means comprise an axis driving card receiving data from a processor included in a PC and operating on the motors driving the different components of the machine in order to provide a desired machining or working program.
The invention provides the following advantages with respect to the prior art status.
At first, since the programmable driven slides are independently driven, it is possible to accurately control the bending tool stroke and speed by using a PC, without mechanically controlling the cams.
The machining of different types of products can be simply obtained by replacing the tool acting on the strip or wire, with a consequent very reduced time for properly setting the machine.
Moreover, the component number is greatly reduced, since the above disclosed prior motion transmitting system is herein omitted.
The independent driving of the press would allow to fully exploit the characteristics of the motor, which can be controlled in a very simple manner by a PC, since it is independent from the remaining part of the machine.
Moreover, the motor driving of the press would allow said press to be arranged outside of the operating circumference of the slides and, moreover, it would afford the possibility of not using the press, as it would not be necessary.
Furthermore, the press motor driven longitudinal axis would allow to easily assemble the molds always at the center of the press, thereby obviating the requirement of performing complex adjusting operations and improving the life of the mold, since any longitudinal stress due to an improper location of the mold in side the press are fully eliminated.
Moreover, the use to of a PC would allow to easily control the longitudinal displacement for properly centering the mold as well as the cross displacement for pressing the workpiece, by timing the press operation with the remaining operations of the machine.
Finally, the programmable pitch roller feeding of the strip or wire being processed is such as to provide an adjustable stroke, which is different from a fixed stroke as in prior mechanical feeding devices.
Actually, even if manually performed, a cross location of the feeding assembly would allow the material to be always accurately centered with respect to the following machining tools, press, slide and so on.
The PC moreover also manages the feeding and timing with the other tools included in the machine.